This invention relates broadly to throttle body assemblies and is particularly concerned with a throttle body assembly having a novel control mechanism useful in providing constant engine idle speed control.
In a vehicle having an internal combustion engine, it is desirable to create as homogeneous a combustible mixture as possible in order to obtain more complete combustion in the cylinders of the engine. The steps toward attainment of the homogeneous mixture begin in a throttle body where fuel is introduced into the induction passage through which air is drawn. The present application discloses a throttle body assembly containing novel throttle blade and air-fuel mixture structure which is beneficial in promoting more homogeneous fuel/air mixture and modulation of said mixture in accordance with engine demand. In the disclosed embodiment, induction air is confined to a central region of the induction passage where the fuel distribution system sprays liquid fuel into the induction airstream. The throttle body assembly is particularly adapted for use in an electronic fuel metering system, generally of the type shown in U.S. Pat. No. 3,935,851 assigned to the same assignee as the present application.
The claimed invention in this application relates to a novel control mechanism useful for engine idle speed control for adjusting the throttle blades, when the engine is in idle, to maintain a substantially constant engine idle speed which is independent of engine load and temperature. Such a constant idle speed control accomplishes better engine performance and avoids fuel waste thereby improving fuel economy.
The foregoing features, advantages, and benefits, along with additional ones, will be seen in the ensuring description and claims which are to be considered in conjunction with the accompanying drawings which disclose an illustrative, but preferred, embodiment of the present invention according to the best mode presently contemplated in carrying out the invention.